Yesterday I realized that probably, while mounting the new crystal to my GMT I may have unflattened the case back as in the picture.
I used this kind of screw press to do the job
and now the case back looks like this, a little pressed inside. The rotor is not affected and is moving freely, my idea is to remove the back and use the same press to try get the thning more flat. What do you think? I wasn't aware this stainless steel back could be so easily deformed.